In continuous ink jet printing, ink is supplied under pressure to a manifold that distributes the ink to a plurality of orifices, typically arranged in linear array(s). The ink is expelled from the orifices in jets which break up due to surface tension in the ink into droplet streams. Ink jet printing is accomplished with these droplet streams by selectively charging and deflecting some droplets from their normal trajectories. The deflected or undeflected droplets are caught and re-circulated and the others are allowed to impinge on a printing surface.
The current process for construction and assembly of the primary components used in planar charging continuous ink jet printers is stack lamination utilizing screened epoxy. However, the use of epoxy has several undesirable effects. For example, application of epoxy requires polymer screens to distribute material appropriately. These screens frequently tear and must be remade, and also must be cleaned with hazardous solvents between each use. Furthermore, the amount of epoxy applied is operator dependent, which can be problematic. Additionally, epoxy must be stored in a freezer to ensure shelf life and viability.
Primary ink jet components are precisely registered to one another after epoxy is applied. The epoxy is then cured with elevated temperatures. The ink jet hardware is constructed with various materials, hence grows thermally and also differentially. The epoxy cross-links the dimensional changes together which can be detrimental to ink jet performance. Cross-linked epoxy is rigid and difficult to remove if tooling or ink jet hardware needs to be cleaned or reclaimed for reuse. Consequently, many ink jet components are destroyed in the process of epoxy removal or component separation during the recovery process. Epoxy at lamination temperature, prior to crosslinking, exhibits extremely low viscosity. This low viscosity promotes wicking into other area of an ink jet printhead that degrades overall performance.
A need has therefore been identified for an improved technique for printhead component joining, whereby the hardware can be reused with little or no cleanup, repositioning of components can be facilitated, construction dwell time is reduced, and concerns of refrigeration, storage and shelf life are eliminated.